How Starbucks borrows money from its customers at a negative 10% interest rate

See the original posting on Boing Boing

This essay from Moneyness by JP Koning is from 2019, but I just came across it. It’s about Starbucks stored value accounts, which come in the form of physical cards but also as smartphone and smartwatch apps. In 2019 customers were holding about $1.6 billion in stored value.